From: Tatsuo Ishii Date: Fri, 22 Sep 2023 13:53:36 +0900 Subject: [PATCH v7 4/7] Row pattern recognition patch (executor). --- src/backend/executor/nodeWindowAgg.c | 853 ++++++++++++++++++++++++++- src/backend/utils/adt/windowfuncs.c | 37 +- src/include/catalog/pg_proc.dat | 6 + src/include/nodes/execnodes.h | 26 + 4 files changed, 909 insertions(+), 13 deletions(-) diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c index 310ac23e3a..84d1b8acaa 100644 --- a/src/backend/executor/nodeWindowAgg.c +++ b/src/backend/executor/nodeWindowAgg.c @@ -36,6 +36,7 @@ #include "access/htup_details.h" #include "catalog/objectaccess.h" #include "catalog/pg_aggregate.h" +#include "catalog/pg_collation_d.h" #include "catalog/pg_proc.h" #include "executor/executor.h" #include "executor/nodeWindowAgg.h" @@ -48,6 +49,7 @@ #include "utils/acl.h" #include "utils/builtins.h" #include "utils/datum.h" +#include "utils/fmgroids.h" #include "utils/expandeddatum.h" #include "utils/lsyscache.h" #include "utils/memutils.h" @@ -182,8 +184,9 @@ static void begin_partition(WindowAggState *winstate); static void spool_tuples(WindowAggState *winstate, int64 pos); static void release_partition(WindowAggState *winstate); -static int row_is_in_frame(WindowAggState *winstate, int64 pos, +static int row_is_in_frame(WindowAggState *winstate, int64 pos, TupleTableSlot *slot); + static void update_frameheadpos(WindowAggState *winstate); static void update_frametailpos(WindowAggState *winstate); static void update_grouptailpos(WindowAggState *winstate); @@ -195,9 +198,32 @@ static Datum GetAggInitVal(Datum textInitVal, Oid transtype); static bool are_peers(WindowAggState *winstate, TupleTableSlot *slot1, TupleTableSlot *slot2); -static bool window_gettupleslot(WindowObject winobj, int64 pos, - TupleTableSlot *slot); +static int WinGetSlotInFrame(WindowObject winobj, TupleTableSlot *slot, + int relpos, int seektype, bool set_mark, + bool *isnull, bool *isout); +static bool window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot); + +static void attno_map(Node *node); +static bool attno_map_walker(Node *node, void *context); +static int row_is_in_reduced_frame(WindowObject winobj, int64 pos); +static bool rpr_is_defined(WindowAggState *winstate); + +static void create_reduced_frame_map(WindowAggState *winstate); +static int get_reduced_frame_map(WindowAggState *winstate, int64 pos); +static void register_reduced_frame_map(WindowAggState *winstate, int64 pos, int val); +static void clear_reduced_frame_map(WindowAggState *winstate); +static void update_reduced_frame(WindowObject winobj, int64 pos); + +static int64 evaluate_pattern(WindowObject winobj, int64 current_pos, + char *vname, StringInfo encoded_str, bool *result); + +static bool get_slots(WindowObject winobj, int64 current_pos); + +static int search_str_set(char *pattern, StringInfo *str_set, int set_size); +static void search_str_set_recurse(char *pattern, StringInfo *str_set, int set_size, int set_index, + int str_index, char *encoded_str, int *resultlen); +static char pattern_initial(WindowAggState *winstate, char *vname); /* * initialize_windowaggregate @@ -673,6 +699,7 @@ eval_windowaggregates(WindowAggState *winstate) WindowObject agg_winobj; TupleTableSlot *agg_row_slot; TupleTableSlot *temp_slot; + bool agg_result_isnull; numaggs = winstate->numaggs; if (numaggs == 0) @@ -778,6 +805,9 @@ eval_windowaggregates(WindowAggState *winstate) * Note that we don't strictly need to restart in the last case, but if * we're going to remove all rows from the aggregation anyway, a restart * surely is faster. + * + * - if RPR is enabled and skip mode is SKIP TO NEXT ROW, + * we restart aggregation too. *---------- */ numaggs_restart = 0; @@ -788,8 +818,11 @@ eval_windowaggregates(WindowAggState *winstate) (winstate->aggregatedbase != winstate->frameheadpos && !OidIsValid(peraggstate->invtransfn_oid)) || (winstate->frameOptions & FRAMEOPTION_EXCLUSION) || - winstate->aggregatedupto <= winstate->frameheadpos) + winstate->aggregatedupto <= winstate->frameheadpos || + (rpr_is_defined(winstate) && + winstate->rpSkipTo == ST_NEXT_ROW)) { + elog(DEBUG1, "peraggstate->restart is set"); peraggstate->restart = true; numaggs_restart++; } @@ -861,8 +894,10 @@ eval_windowaggregates(WindowAggState *winstate) * If we created a mark pointer for aggregates, keep it pushed up to frame * head, so that tuplestore can discard unnecessary rows. */ +#ifdef NOT_USED if (agg_winobj->markptr >= 0) WinSetMarkPosition(agg_winobj, winstate->frameheadpos); +#endif /* * Now restart the aggregates that require it. @@ -917,6 +952,29 @@ eval_windowaggregates(WindowAggState *winstate) { winstate->aggregatedupto = winstate->frameheadpos; ExecClearTuple(agg_row_slot); + + /* + * If RPR is defined, we do not use aggregatedupto_nonrestarted. To + * avoid assertion failure below, we reset aggregatedupto_nonrestarted + * to frameheadpos. + */ + if (rpr_is_defined(winstate)) + aggregatedupto_nonrestarted = winstate->frameheadpos; + } + + agg_result_isnull = false; + /* RPR is defined? */ + if (rpr_is_defined(winstate)) + { + /* + * If the skip mode is SKIP TO PAST LAST ROW and we already know that + * current row is a skipped row, we don't need to accumulate rows, + * just return NULL. Note that for unamtched row, we need to do + * aggregation so that count(*) shows 0, rather than NULL. + */ + if (winstate->rpSkipTo == ST_PAST_LAST_ROW && + get_reduced_frame_map(winstate, winstate->currentpos) == RF_SKIPPED) + agg_result_isnull = true; } /* @@ -930,6 +988,11 @@ eval_windowaggregates(WindowAggState *winstate) { int ret; + elog(DEBUG1, "===== loop in frame starts: " INT64_FORMAT, winstate->aggregatedupto); + + if (agg_result_isnull) + break; + /* Fetch next row if we didn't already */ if (TupIsNull(agg_row_slot)) { @@ -945,9 +1008,28 @@ eval_windowaggregates(WindowAggState *winstate) ret = row_is_in_frame(winstate, winstate->aggregatedupto, agg_row_slot); if (ret < 0) break; + if (ret == 0) goto next_tuple; + if (rpr_is_defined(winstate)) + { + /* + * If the row status at currentpos is already decided and current + * row status is not decided yet, it means we passed the last + * reduced frame. Time to break the loop. + */ + if (get_reduced_frame_map(winstate, winstate->currentpos) != RF_NOT_DETERMINED && + get_reduced_frame_map(winstate, winstate->aggregatedupto) == RF_NOT_DETERMINED) + break; + /* + * Otherwise we need to calculate the reduced frame. + */ + ret = row_is_in_reduced_frame(winstate->agg_winobj, winstate->aggregatedupto); + if (ret == -1) /* unmatched row */ + break; + } + /* Set tuple context for evaluation of aggregate arguments */ winstate->tmpcontext->ecxt_outertuple = agg_row_slot; @@ -976,6 +1058,7 @@ next_tuple: ExecClearTuple(agg_row_slot); } + /* The frame's end is not supposed to move backwards, ever */ Assert(aggregatedupto_nonrestarted <= winstate->aggregatedupto); @@ -996,6 +1079,16 @@ next_tuple: peraggstate, result, isnull); + /* + * RPR is defined and we just return NULL because skip mode is SKIP + * TO PAST LAST ROW and current row is skipped row. + */ + if (agg_result_isnull) + { + *isnull = true; + *result = (Datum) 0; + } + /* * save the result in case next row shares the same frame. * @@ -1090,6 +1183,7 @@ begin_partition(WindowAggState *winstate) winstate->framehead_valid = false; winstate->frametail_valid = false; winstate->grouptail_valid = false; + create_reduced_frame_map(winstate); winstate->spooled_rows = 0; winstate->currentpos = 0; winstate->frameheadpos = 0; @@ -2053,6 +2147,8 @@ ExecWindowAgg(PlanState *pstate) CHECK_FOR_INTERRUPTS(); + elog(DEBUG1, "ExecWindowAgg called. pos: " INT64_FORMAT , winstate->currentpos); + if (winstate->status == WINDOWAGG_DONE) return NULL; @@ -2221,6 +2317,17 @@ ExecWindowAgg(PlanState *pstate) /* don't evaluate the window functions when we're in pass-through mode */ if (winstate->status == WINDOWAGG_RUN) { + /* + * If RPR is defined and skip mode is next row, we need to clear existing + * reduced frame info so that we newly calculate the info starting from + * current row. + */ + if (rpr_is_defined(winstate)) + { + if (winstate->rpSkipTo == ST_NEXT_ROW) + clear_reduced_frame_map(winstate); + } + /* * Evaluate true window functions */ @@ -2388,6 +2495,9 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags) TupleDesc scanDesc; ListCell *l; + TargetEntry *te; + Expr *expr; + /* check for unsupported flags */ Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK))); @@ -2483,6 +2593,16 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags) winstate->temp_slot_2 = ExecInitExtraTupleSlot(estate, scanDesc, &TTSOpsMinimalTuple); + winstate->prev_slot = ExecInitExtraTupleSlot(estate, scanDesc, + &TTSOpsMinimalTuple); + + winstate->next_slot = ExecInitExtraTupleSlot(estate, scanDesc, + &TTSOpsMinimalTuple); + + winstate->null_slot = ExecInitExtraTupleSlot(estate, scanDesc, + &TTSOpsMinimalTuple); + winstate->null_slot = ExecStoreAllNullTuple(winstate->null_slot); + /* * create frame head and tail slots only if needed (must create slots in * exactly the same cases that update_frameheadpos and update_frametailpos @@ -2667,6 +2787,39 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags) winstate->inRangeAsc = node->inRangeAsc; winstate->inRangeNullsFirst = node->inRangeNullsFirst; + /* Set up SKIP TO type */ + winstate->rpSkipTo = node->rpSkipTo; + /* Set up row pattern recognition PATTERN clause */ + winstate->patternVariableList = node->patternVariable; + winstate->patternRegexpList = node->patternRegexp; + + /* Set up row pattern recognition DEFINE clause */ + winstate->defineInitial = node->defineInitial; + winstate->defineVariableList = NIL; + winstate->defineClauseList = NIL; + if (node->defineClause != NIL) + { + /* + * Tweak arg var of PREV/NEXT so that it refers to scan/inner slot. + */ + foreach(l, node->defineClause) + { + char *name; + ExprState *exps; + + te = lfirst(l); + name = te->resname; + expr = te->expr; + + elog(DEBUG1, "defineVariable name: %s", name); + winstate->defineVariableList = lappend(winstate->defineVariableList, + makeString(pstrdup(name))); + attno_map((Node *)expr); + exps = ExecInitExpr(expr, (PlanState *) winstate); + winstate->defineClauseList = lappend(winstate->defineClauseList, exps); + } + } + winstate->all_first = true; winstate->partition_spooled = false; winstate->more_partitions = false; @@ -2674,6 +2827,57 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags) return winstate; } +/* + * Rewrite varno of Var node that is the argument of PREV/NET so that it sees + * scan tuple (PREV) or inner tuple (NEXT). + */ +static void +attno_map(Node *node) +{ + (void) expression_tree_walker(node, attno_map_walker, NULL); +} + +static bool +attno_map_walker(Node *node, void *context) +{ + FuncExpr *func; + int nargs; + Expr *expr; + Var *var; + + if (node == NULL) + return false; + + if (IsA(node, FuncExpr)) + { + func = (FuncExpr *)node; + + if (func->funcid == F_PREV || func->funcid == F_NEXT) + { + /* sanity check */ + nargs = list_length(func->args); + if (list_length(func->args) != 1) + elog(ERROR, "PREV/NEXT must have 1 argument but function %d has %d args", func->funcid, nargs); + + expr = (Expr *) lfirst(list_head(func->args)); + if (!IsA(expr, Var)) + elog(ERROR, "PREV/NEXT's arg is not Var"); /* XXX: is it possible that arg type is Const? */ + var = (Var *)expr; + + if (func->funcid == F_PREV) + /* + * Rewrite varno from OUTER_VAR to regular var no so that the + * var references scan tuple. + */ + var->varno = var->varnosyn; + else + var->varno = INNER_VAR; + elog(DEBUG1, "PREV/NEXT's varno is rewritten to: %d", var->varno); + } + } + return expression_tree_walker(node, attno_map_walker, NULL); +} + /* ----------------- * ExecEndWindowAgg * ----------------- @@ -2691,6 +2895,8 @@ ExecEndWindowAgg(WindowAggState *node) ExecClearTuple(node->agg_row_slot); ExecClearTuple(node->temp_slot_1); ExecClearTuple(node->temp_slot_2); + ExecClearTuple(node->prev_slot); + ExecClearTuple(node->next_slot); if (node->framehead_slot) ExecClearTuple(node->framehead_slot); if (node->frametail_slot) @@ -2740,6 +2946,8 @@ ExecReScanWindowAgg(WindowAggState *node) ExecClearTuple(node->agg_row_slot); ExecClearTuple(node->temp_slot_1); ExecClearTuple(node->temp_slot_2); + ExecClearTuple(node->prev_slot); + ExecClearTuple(node->next_slot); if (node->framehead_slot) ExecClearTuple(node->framehead_slot); if (node->frametail_slot) @@ -3100,7 +3308,7 @@ window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot) return false; if (pos < winobj->markpos) - elog(ERROR, "cannot fetch row before WindowObject's mark position"); + elog(ERROR, "cannot fetch row: " INT64_FORMAT " before WindowObject's mark position: " INT64_FORMAT, pos, winobj->markpos ); oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory); @@ -3420,14 +3628,54 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno, WindowAggState *winstate; ExprContext *econtext; TupleTableSlot *slot; - int64 abs_pos; - int64 mark_pos; Assert(WindowObjectIsValid(winobj)); winstate = winobj->winstate; econtext = winstate->ss.ps.ps_ExprContext; slot = winstate->temp_slot_1; + if (WinGetSlotInFrame(winobj, slot, + relpos, seektype, set_mark, + isnull, isout) == 0) + { + econtext->ecxt_outertuple = slot; + return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno), + econtext, isnull); + } + + if (isout) + *isout = true; + *isnull = true; + return (Datum) 0; +} + +/* + * WinGetSlotInFrame + * slot: TupleTableSlot to store the result + * relpos: signed rowcount offset from the seek position + * seektype: WINDOW_SEEK_HEAD or WINDOW_SEEK_TAIL + * set_mark: If the row is found/in frame and set_mark is true, the mark is + * moved to the row as a side-effect. + * isnull: output argument, receives isnull status of result + * isout: output argument, set to indicate whether target row position + * is out of frame (can pass NULL if caller doesn't care about this) + * + * Returns 0 if we successfullt got the slot. false if out of frame. + * (also isout is set) + */ +static int +WinGetSlotInFrame(WindowObject winobj, TupleTableSlot *slot, + int relpos, int seektype, bool set_mark, + bool *isnull, bool *isout) +{ + WindowAggState *winstate; + int64 abs_pos; + int64 mark_pos; + int num_reduced_frame; + + Assert(WindowObjectIsValid(winobj)); + winstate = winobj->winstate; + switch (seektype) { case WINDOW_SEEK_CURRENT: @@ -3494,11 +3742,21 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno, winstate->frameOptions); break; } + num_reduced_frame = row_is_in_reduced_frame(winobj, winstate->frameheadpos); + if (num_reduced_frame < 0) + goto out_of_frame; + else if (num_reduced_frame > 0) + if (relpos >= num_reduced_frame) + goto out_of_frame; break; case WINDOW_SEEK_TAIL: /* rejecting relpos > 0 is easy and simplifies code below */ if (relpos > 0) goto out_of_frame; + + /* RPR cares about frame head pos. Need to call update_frameheadpos */ + update_frameheadpos(winstate); + update_frametailpos(winstate); abs_pos = winstate->frametailpos - 1 + relpos; @@ -3565,6 +3823,12 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno, mark_pos = 0; /* keep compiler quiet */ break; } + + num_reduced_frame = row_is_in_reduced_frame(winobj, winstate->frameheadpos + relpos); + if (num_reduced_frame < 0) + goto out_of_frame; + else if (num_reduced_frame > 0) + abs_pos = winstate->frameheadpos + relpos + num_reduced_frame - 1; break; default: elog(ERROR, "unrecognized window seek type: %d", seektype); @@ -3583,15 +3847,13 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno, *isout = false; if (set_mark) WinSetMarkPosition(winobj, mark_pos); - econtext->ecxt_outertuple = slot; - return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno), - econtext, isnull); + return 0; out_of_frame: if (isout) *isout = true; *isnull = true; - return (Datum) 0; + return -1; } /* @@ -3622,3 +3884,572 @@ WinGetFuncArgCurrent(WindowObject winobj, int argno, bool *isnull) return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno), econtext, isnull); } + +/* + * rpr_is_defined + * return true if Row pattern recognition is defined. + */ +static +bool rpr_is_defined(WindowAggState *winstate) +{ + return winstate->patternVariableList != NIL; +} + +/* + * row_is_in_reduced_frame + * Determine whether a row is in the current row's reduced window frame according + * to row pattern matching + * + * The row must has been already determined that it is in a full window frame + * and fetched it into slot. + * + * Returns: + * = 0, RPR is not defined. + * >0, if the row is the first in the reduced frame. Return the number of rows in the reduced frame. + * -1, if the row is unmatched row + * -2, if the row is in the reduced frame but needed to be skipped because of + * AFTER MATCH SKIP PAST LAST ROW + */ +static +int row_is_in_reduced_frame(WindowObject winobj, int64 pos) +{ + WindowAggState *winstate = winobj->winstate; + int state; + int rtn; + + if (!rpr_is_defined(winstate)) + { + /* + * RPR is not defined. Assume that we are always in the the reduced + * window frame. + */ + rtn = 0; + elog(DEBUG1, "row_is_in_reduced_frame returns %d: pos: " INT64_FORMAT, rtn, pos); + return rtn; + } + + state = get_reduced_frame_map(winstate, pos); + + if (state == RF_NOT_DETERMINED) + { + update_frameheadpos(winstate); + update_reduced_frame(winobj, pos); + } + + state = get_reduced_frame_map(winstate, pos); + + switch (state) + { + int64 i; + int num_reduced_rows; + + case RF_FRAME_HEAD: + num_reduced_rows = 1; + for (i = pos + 1; get_reduced_frame_map(winstate,i) == RF_SKIPPED; i++) + num_reduced_rows++; + rtn = num_reduced_rows; + break; + + case RF_SKIPPED: + rtn = -2; + break; + + case RF_UNMATCHED: + rtn = -1; + break; + + default: + elog(ERROR, "Unrecognized state: %d at: " INT64_FORMAT, state, pos); + break; + } + + elog(DEBUG1, "row_is_in_reduced_frame returns %d: pos: " INT64_FORMAT, rtn, pos); + return rtn; +} + +#define REDUCED_FRAME_MAP_INIT_SIZE 1024L + +/* + * Create reduced frame map + */ +static +void create_reduced_frame_map(WindowAggState *winstate) +{ + winstate->reduced_frame_map = + MemoryContextAlloc(winstate->partcontext, REDUCED_FRAME_MAP_INIT_SIZE); + winstate->alloc_sz = REDUCED_FRAME_MAP_INIT_SIZE; + clear_reduced_frame_map(winstate); +} + +/* + * Clear reduced frame map + */ +static +void clear_reduced_frame_map(WindowAggState *winstate) +{ + Assert(winstate->reduced_frame_map != NULL); + MemSet(winstate->reduced_frame_map, RF_NOT_DETERMINED, + winstate->alloc_sz); +} + +/* + * Get reduced frame map specified by pos + */ +static +int get_reduced_frame_map(WindowAggState *winstate, int64 pos) +{ + Assert(winstate->reduced_frame_map != NULL); + + if (pos < 0 || pos >= winstate->alloc_sz) + elog(ERROR, "wrong pos: " INT64_FORMAT, pos); + + return winstate->reduced_frame_map[pos]; +} + +/* + * Add/replace reduced frame map member at pos. + * If there's no enough space, expand the map. + */ +static +void register_reduced_frame_map(WindowAggState *winstate, int64 pos, int val) +{ + int64 realloc_sz; + + Assert(winstate->reduced_frame_map != NULL); + + if (pos < 0) + elog(ERROR, "wrong pos: " INT64_FORMAT, pos); + + if (pos > winstate->alloc_sz - 1) + { + realloc_sz = winstate->alloc_sz * 2; + + winstate->reduced_frame_map = + repalloc(winstate->reduced_frame_map, realloc_sz); + + MemSet(winstate->reduced_frame_map + winstate->alloc_sz, + RF_NOT_DETERMINED, realloc_sz - winstate->alloc_sz); + + winstate->alloc_sz = realloc_sz; + } + + winstate->reduced_frame_map[pos] = val; +} + +/* + * update_reduced_frame + * Update reduced frame info. + */ +static +void update_reduced_frame(WindowObject winobj, int64 pos) +{ + WindowAggState *winstate = winobj->winstate; + ListCell *lc1, *lc2; + bool expression_result; + int num_matched_rows; + int64 original_pos; + bool anymatch; + StringInfo encoded_str; + StringInfo pattern_str = makeStringInfo(); + + /* + * Array of pattern variables evaluted to true. + * Each character corresponds to pattern variable. + * Example: + * str_set[0] = "AB"; + * str_set[1] = "AC"; + * In this case at row 0 A and B are true, and A and C are true in row 1. + */ + #define ENCODED_STR_ARRAY_ALLOC_SIZE 128 + StringInfo *str_set = NULL; + int str_set_index; + int str_set_size; + + /* save original pos */ + original_pos = pos; + + /* + * Loop over until none of pattern matches or encounters end of frame. + */ + for (;;) + { + int64 result_pos = -1; + + /* + * Loop over each PATTERN variable. + */ + anymatch = false; + encoded_str = makeStringInfo(); + + forboth(lc1, winstate->patternVariableList, lc2, winstate->patternRegexpList) + { + char *vname = strVal(lfirst(lc1)); + char *quantifier = strVal(lfirst(lc2)); + + elog(DEBUG1, "pos: " INT64_FORMAT " pattern vname: %s quantifier: %s", pos, vname, quantifier); + + expression_result = false; + + /* evaluate row pattern against current row */ + result_pos = evaluate_pattern(winobj, pos, vname, encoded_str, &expression_result); + if (expression_result) + { + elog(DEBUG1, "expression result is true"); + anymatch = true; + } + + /* + * If out of frame, we are done. + */ + if (result_pos < 0) + break; + } + + if (!anymatch) + { + /* none of patterns matched. */ + break; + } + + /* build encoded string array */ + if (str_set == NULL) + { + str_set_index = 0; + str_set_size = ENCODED_STR_ARRAY_ALLOC_SIZE * sizeof(StringInfo); + str_set = palloc(str_set_size); + } + + str_set[str_set_index++] = encoded_str; + + elog(DEBUG1, "pos: " INT64_FORMAT " str_set_index: %d encoded_str: %s", pos, str_set_index, encoded_str->data); + + if (str_set_index >= str_set_size) + { + str_set_size *= 2; + str_set = repalloc(str_set, str_set_size); + } + + /* move to next row */ + pos++; + + if (result_pos < 0) + { + /* out of frame */ + break; + } + } + + if (str_set == NULL) + { + /* no match found in the first row */ + register_reduced_frame_map(winstate, original_pos, RF_UNMATCHED); + return; + } + + elog(DEBUG2, "pos: " INT64_FORMAT " encoded_str: %s", pos, encoded_str->data); + + /* build regular expression */ + pattern_str = makeStringInfo(); + appendStringInfoChar(pattern_str, '^'); + forboth (lc1, winstate->patternVariableList, lc2, winstate->patternRegexpList) + { + char *vname = strVal(lfirst(lc1)); + char *quantifier = strVal(lfirst(lc2)); + char initial; + + initial = pattern_initial(winstate, vname); + Assert(initial != 0); + appendStringInfoChar(pattern_str, initial); + if (quantifier[0]) + appendStringInfoChar(pattern_str, quantifier[0]); + elog(DEBUG1, "vname: %s initial: %c quantifier: %s", vname, initial, quantifier); + } + + elog(DEBUG2, "pos: " INT64_FORMAT " pattern: %s", pos, pattern_str->data); + + /* look for matching pattern variable sequence */ + num_matched_rows = search_str_set(pattern_str->data, str_set, str_set_index); + /* + * We are at the first row in the reduced frame. Save the number of + * matched rows as the number of rows in the reduced frame. + */ + if (num_matched_rows <= 0) + { + /* no match */ + register_reduced_frame_map(winstate, original_pos, RF_UNMATCHED); + } + else + { + int64 i; + + register_reduced_frame_map(winstate, original_pos, RF_FRAME_HEAD); + + for (i = original_pos + 1; i < original_pos + num_matched_rows; i++) + { + register_reduced_frame_map(winstate, i, RF_SKIPPED); + } + } + + return; +} + +/* + * Perform regex search pattern against encoded string array str_set. + * returns the number of longest matching rows. + * str_set: array of encoded string. Each array element corresponds to each + * row. + * set_size: size of set_str array. + */ +static +int search_str_set(char *pattern, StringInfo *str_set, int set_size) +{ + char *encoded_str = palloc0(set_size+1); + int resultlen = 0; + + search_str_set_recurse(pattern, str_set, set_size, 0, 0, + encoded_str, &resultlen); + elog(DEBUG1, "search_str_set returns %d", resultlen); + return resultlen; +} + +/* + * Workhorse of search_str_set. + * + * Recurse among matched pattern variables in a row. The max recursion depth + * is number of pattern variables matched in a row. + */ +static +void search_str_set_recurse(char *pattern, StringInfo *str_set, + int set_size, int set_index, int str_index, + char *encoded_str, int *resultlen) +{ + for (;;) + { + char c; + + c = str_set[set_index]->data[str_index]; + if (c == '\0') + return; + encoded_str[set_index] = c; + set_index++; + + if (set_index >= set_size) + { + Datum d; + text *res; + char *substr; + + /* + * We first perform pattern matching using regexp_instr, then call + * textregexsubstr to get matched substring to know how long the + * matched string is. That is the number of rows in the reduced window + * frame. The reason why we can't call textregexsubstr in the first + * place is, it errors out if pattern does not match. + */ + if (DatumGetInt32(DirectFunctionCall2Coll(regexp_instr, DEFAULT_COLLATION_OID, + PointerGetDatum(cstring_to_text(encoded_str)), + PointerGetDatum(cstring_to_text(pattern)))) > 0) + { + d = DirectFunctionCall2Coll(textregexsubstr, + DEFAULT_COLLATION_OID, + PointerGetDatum(cstring_to_text(encoded_str)), + PointerGetDatum(cstring_to_text(pattern))); + if (d != 0) + { + int len; + + res = DatumGetTextPP(d); + substr = text_to_cstring(res); + len = strlen(substr); + if (len > *resultlen) + /* remember the longest match */ + *resultlen = len; + } + } + return; + } + else + search_str_set_recurse(pattern, str_set, set_size, set_index, str_index + 1, + encoded_str, resultlen); + } +} + +/* + * Evaluate expression associated with PATTERN variable vname. + * relpos is relative row position in a frame (starting from 0). + * "quantifier" is the quatifier part of the PATTERN regular expression. + * Currently only '+' is allowed. + * result is out paramater representing the expression evaluation result + * is true of false. + * Return values are: + * >=0: the last match absolute row position + * other wise out of frame. + */ +static +int64 evaluate_pattern(WindowObject winobj, int64 current_pos, + char *vname, StringInfo encoded_str, bool *result) +{ + WindowAggState *winstate = winobj->winstate; + ExprContext *econtext = winstate->ss.ps.ps_ExprContext; + ListCell *lc1, *lc2, *lc3; + ExprState *pat; + Datum eval_result; + bool out_of_frame = false; + bool isnull; + + forthree (lc1, winstate->defineVariableList, lc2, winstate->defineClauseList, lc3, winstate->defineInitial) + { + char initial; + char *name = strVal(lfirst(lc1)); + + if (strcmp(vname, name)) + continue; + + initial = *(strVal(lfirst(lc3))); + + /* set expression to evaluate */ + pat = lfirst(lc2); + + /* get current, previous and next tuples */ + if (!get_slots(winobj, current_pos)) + { + out_of_frame = true; + } + else + { + /* evaluate the expression */ + eval_result = ExecEvalExpr(pat, econtext, &isnull); + if (isnull) + { + /* expression is NULL */ + elog(DEBUG1, "expression for %s is NULL at row: " INT64_FORMAT, vname, current_pos); + *result = false; + } + else + { + if (!DatumGetBool(eval_result)) + { + /* expression is false */ + elog(DEBUG1, "expression for %s is false at row: " INT64_FORMAT, vname, current_pos); + *result = false; + } + else + { + /* expression is true */ + elog(DEBUG1, "expression for %s is true at row: " INT64_FORMAT, vname, current_pos); + appendStringInfoChar(encoded_str, initial); + *result = true; + } + } + break; + } + + if (out_of_frame) + { + *result = false; + return -1; + } + } + return current_pos; +} + +/* + * Get current, previous and next tuples. + * Returns false if current row is out of partition/full frame. + */ +static +bool get_slots(WindowObject winobj, int64 current_pos) +{ + WindowAggState *winstate = winobj->winstate; + TupleTableSlot *slot; + int ret; + ExprContext *econtext; + + econtext = winstate->ss.ps.ps_ExprContext; + + /* set up current row tuple slot */ + slot = winstate->temp_slot_1; + if (!window_gettupleslot(winobj, current_pos, slot)) + { + elog(DEBUG1, "current row is out of partition at:" INT64_FORMAT, current_pos); + return false; + + ret = row_is_in_frame(winstate, current_pos, slot); + if (ret <= 0) + { + elog(DEBUG1, "current row is out of frame at: " INT64_FORMAT, current_pos); + return false; + } + } + econtext->ecxt_outertuple = slot; + + /* for PREV */ + if (current_pos > 0) + { + slot = winstate->prev_slot; + if (!window_gettupleslot(winobj, current_pos - 1, slot)) + { + elog(DEBUG1, "previous row is out of partition at: " INT64_FORMAT, current_pos - 1); + econtext->ecxt_scantuple = winstate->null_slot; + } + else + { + ret = row_is_in_frame(winstate, current_pos - 1, slot); + if (ret <= 0) + { + elog(DEBUG1, "previous row is out of frame at: " INT64_FORMAT, current_pos - 1); + econtext->ecxt_scantuple = winstate->null_slot; + } + else + { + econtext->ecxt_scantuple = slot; + } + } + } + else + econtext->ecxt_scantuple = winstate->null_slot; + + /* for NEXT */ + slot = winstate->next_slot; + if (!window_gettupleslot(winobj, current_pos + 1, slot)) + { + elog(DEBUG1, "next row is out of partiton at: " INT64_FORMAT, current_pos + 1); + econtext->ecxt_innertuple = winstate->null_slot; + } + else + { + ret = row_is_in_frame(winstate, current_pos + 1, slot); + if (ret <= 0) + { + elog(DEBUG1, "next row is out of frame at: " INT64_FORMAT, current_pos + 1); + econtext->ecxt_innertuple = winstate->null_slot; + } + else + econtext->ecxt_innertuple = slot; + } + return true; +} + +/* + * Return pattern variable initial character + * matching with pattern variable name vname. + * If not found, return 0. + */ +static +char pattern_initial(WindowAggState *winstate, char *vname) +{ + char initial; + char *name; + ListCell *lc1, *lc2; + + forboth (lc1, winstate->defineVariableList, lc2, winstate->defineInitial) + { + name = strVal(lfirst(lc1)); /* DEFINE variable name */ + initial = *(strVal(lfirst(lc2))); /* DEFINE variable initial */ + + + if (!strcmp(name, vname)) + return initial; /* found */ + } + return 0; +} diff --git a/src/backend/utils/adt/windowfuncs.c b/src/backend/utils/adt/windowfuncs.c index b87a624fb2..9ebcc7b5d2 100644 --- a/src/backend/utils/adt/windowfuncs.c +++ b/src/backend/utils/adt/windowfuncs.c @@ -13,6 +13,9 @@ */ #include "postgres.h" +#include "catalog/pg_collation_d.h" +#include "executor/executor.h" +#include "nodes/execnodes.h" #include "nodes/supportnodes.h" #include "utils/builtins.h" #include "windowapi.h" @@ -36,11 +39,19 @@ typedef struct int64 remainder; /* (total rows) % (bucket num) */ } ntile_context; +/* + * rpr process information. + * Used for AFTER MATCH SKIP PAST LAST ROW + */ +typedef struct SkipContext +{ + int64 pos; /* last row absolute position */ +} SkipContext; + static bool rank_up(WindowObject winobj); static Datum leadlag_common(FunctionCallInfo fcinfo, bool forward, bool withoffset, bool withdefault); - /* * utility routine for *_rank functions. */ @@ -673,7 +684,7 @@ window_last_value(PG_FUNCTION_ARGS) bool isnull; result = WinGetFuncArgInFrame(winobj, 0, - 0, WINDOW_SEEK_TAIL, true, + 0, WINDOW_SEEK_TAIL, false, &isnull, NULL); if (isnull) PG_RETURN_NULL(); @@ -713,3 +724,25 @@ window_nth_value(PG_FUNCTION_ARGS) PG_RETURN_DATUM(result); } + +/* + * prev + * Dummy function to invoke RPR's navigation operator "PREV". + * This is *not* a window function. + */ +Datum +window_prev(PG_FUNCTION_ARGS) +{ + PG_RETURN_DATUM(PG_GETARG_DATUM(0)); +} + +/* + * next + * Dummy function to invoke RPR's navigation operation "NEXT". + * This is *not* a window function. + */ +Datum +window_next(PG_FUNCTION_ARGS) +{ + PG_RETURN_DATUM(PG_GETARG_DATUM(0)); +} diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 9805bc6118..d20f803cf5 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -10416,6 +10416,12 @@ { oid => '3114', descr => 'fetch the Nth row value', proname => 'nth_value', prokind => 'w', prorettype => 'anyelement', proargtypes => 'anyelement int4', prosrc => 'window_nth_value' }, +{ oid => '6122', descr => 'previous value', + proname => 'prev', provolatile => 's', prorettype => 'anyelement', + proargtypes => 'anyelement', prosrc => 'window_prev' }, +{ oid => '6123', descr => 'next value', + proname => 'next', provolatile => 's', prorettype => 'anyelement', + proargtypes => 'anyelement', prosrc => 'window_next' }, # functions for range types { oid => '3832', descr => 'I/O', diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index cb714f4a19..63feb68f60 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -2471,6 +2471,11 @@ typedef enum WindowAggStatus * tuples during spool */ } WindowAggStatus; +#define RF_NOT_DETERMINED 0 +#define RF_FRAME_HEAD 1 +#define RF_SKIPPED 2 +#define RF_UNMATCHED 3 + typedef struct WindowAggState { ScanState ss; /* its first field is NodeTag */ @@ -2519,6 +2524,15 @@ typedef struct WindowAggState int64 groupheadpos; /* current row's peer group head position */ int64 grouptailpos; /* " " " " tail position (group end+1) */ + /* these fields are used in Row pattern recognition: */ + RPSkipTo rpSkipTo; /* Row Pattern Skip To type */ + List *patternVariableList; /* list of row pattern variables names (list of String) */ + List *patternRegexpList; /* list of row pattern regular expressions ('+' or ''. list of String) */ + List *defineVariableList; /* list of row pattern definition variables (list of String) */ + List *defineClauseList; /* expression for row pattern definition + * search conditions ExprState list */ + List *defineInitial; /* list of row pattern definition variable initials (list of String) */ + MemoryContext partcontext; /* context for partition-lifespan data */ MemoryContext aggcontext; /* shared context for aggregate working data */ MemoryContext curaggcontext; /* current aggregate's working data */ @@ -2555,6 +2569,18 @@ typedef struct WindowAggState TupleTableSlot *agg_row_slot; TupleTableSlot *temp_slot_1; TupleTableSlot *temp_slot_2; + + /* temporary slots for RPR */ + TupleTableSlot *prev_slot; /* PREV row navigation operator */ + TupleTableSlot *next_slot; /* NEXT row navigation operator */ + TupleTableSlot *null_slot; /* all NULL slot */ + + /* + * Each byte corresponds to a row positioned at absolute its pos in + * partition. See above definition for RF_* + */ + char *reduced_frame_map; + int64 alloc_sz; /* size of the map */ } WindowAggState; /* ---------------- -- 2.25.1 ----Next_Part(Fri_Sep_22_14_16_40_2023_530)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v7-0005-Row-pattern-recognition-patch-docs.patch"